Electronic Specialties' Digital Tach/Advance Timing Light, no. 125, is professional grade and measures ignition spark advance from 0 degrees to 90 degrees. High visibility LEDs display the engine's rpm and degrees advance. The tool measures engine speed on both two- and four-stroke engines up to 9,999 rpm. The timing light features a bright xenon flash at all speeds, features a detachable/replaceable cable set and works on 12V electrical systems.